KR102619010B1 - Plasma chamber to change the installation location of the ferrite core - Google Patents

Abstract

The present invention relates to a plasma chamber in which the installation position of the ferrite core has been changed. In the plasma chamber having a toroidal-shaped plasma channel of the present invention, the plasma chamber includes a first chamber block including a portion of the plasma channel and having a gas inlet for supplying gas into the plasma chamber; a third chamber block including a portion of the plasma channel and having a gas outlet for discharging gas activated within the plasma chamber to the outside; and a second chamber block that connects the first chamber block and the third chamber block and includes a plasma channel continuous with the plasma channel, and is wrapped around the plasma channel, either the first chamber block or the third chamber block. Includes a ferrite core installed in one. According to the plasma chamber in which the installation position of the ferrite core of the present invention has been changed, the ferrite core is installed in the plasma channel provided with the gas inlet or gas outlet, thereby increasing the reaction rate between the gas supplied into the plasma chamber and the plasma to generate activated gas. This can increase the discharge rate. Additionally, the amount of gas used can be reduced by increasing the reaction rate between gas and plasma.

Description

Plasma chamber with changed installation location of the ferrite core {PLASMA CHAMBER TO CHANGE THE INSTALLATION LOCATION OF THE FERRITE CORE}

The present invention relates to a plasma chamber in which the installation position of the ferrite core has been changed, and more specifically, to a plasma chamber in which the installation position of the ferrite core for supplying gas activated by plasma has been changed.

Plasma discharges can be used to excite gases to produce activated gases containing ions, free radicals, atoms, and molecules. Activated gases are used in a variety of industrial and scientific applications, including processing solid materials such as semiconductor wafers, powders, and other gases. The parameters of the plasma and the conditions regarding its exposure to the materials being processed vary widely depending on the field of technology. For example, some fields require that ions be used with low kinetic energies (i.e., a few electron volts) because the materials being processed are susceptible to damage. Other applications, such as anisotropic etching or planarized insulator deposition, require the use of ions with high kinetic energies. Other applications, such as reactive ion beam etching, require precise control of ion energy.

Some fields require direct exposure of the material being processed to high density plasma. One of these fields is generating ion-activated chemical reactions. Other such areas include the etching of high aspect ratio structures and material deposition therein. Other fields require a neutral activated gas containing atoms and activated molecules, while the material being processed is shielded from the plasma, because the material is susceptible to damage by ions or because the processing process has high selectivity requirements. do.

Various plasma sources can generate plasma in a variety of ways, including DC discharge, radio frequency (RF) discharge, and microwave discharge. DC discharge is achieved by applying an electric potential between two electrodes in a gas. RF discharge is achieved by electrostatic or inductive coupling of energy from a power source into the plasma. Parallel plates are commonly used to inductively couple energy into a plasma. Induction coils are commonly used to induce electric current in a plasma. Microwave discharge is achieved by coupling microwave energy directly through a microwave pass-through window into a discharge chamber containing the gas. Microwave discharge can be used to support a wide range of discharge conditions, including highly ionized electron cyclone resonance (ECR) plasmas.

Compared to microwave or other types of RF plasma sources, toroidal plasma sources have advantages in low electric fields, low plasma chamber corrosion, compactness, and cost effectiveness. Toroidal plasma sources operate at low electric fields and inherently eliminate the current-termination electrode and associated cathode potential drop. Low plasma chamber corrosion allows toroidal plasma sources to operate at higher power densities than other plasma sources. Additionally, by using a high-permeability ferrite core to efficiently couple electromagnetic energy to the plasma, the toroidal plasma chamber can operate at relatively low RF frequencies, lowering power supply costs. Toroidal plasma chambers have been used to generate chemically active gases containing fluorine, oxygen, hydrogen, nitrogen, etc. for the processing of semiconductor wafers, flat panel displays, and various materials.

The gas supplied through the gas inlet of the toroidal plasma chamber moves along the toroidal plasma channel inside the chamber and reacts with plasma to generate activated gas. The flow of gas within the plasma chamber acts as an impedance. It is desirable that all the injected gases react with the plasma and are discharged as activated gas, but there are gases that are discharged without reacting with the plasma. Gas discharged without reacting with plasma affects the wafer processing process or cleaning process. Since gas supplied in an unreacted state is discharged as is, costs may increase due to unnecessary gas supply. Therefore, efforts are required to increase the rate at which the gas supplied to the chamber reacts with the plasma and is discharged as activated gas.

The object of the present invention is to provide a plasma chamber in which the installation position of the ferrite core is changed, which can improve the rate of discharge as activated gas by increasing the reaction rate between the gas supplied into the chamber and the plasma by changing the installation position of the ferrite core. There is a purpose.

The present invention relates to a plasma chamber in which the installation position of the ferrite core has been changed. In the plasma chamber having a toroidal-shaped plasma channel of the present invention, the plasma chamber includes a first chamber block including a portion of the plasma channel and having a gas inlet for supplying gas into the plasma chamber; a third chamber block including a portion of the plasma channel and having a gas outlet for discharging gas activated within the plasma chamber to the outside; and a second chamber block connecting the first chamber block and the third chamber block and including a plasma channel continuous with the plasma channel, wherein the first chamber block or the third chamber block is wrapped around the plasma channel. It contains a ferrite core installed in one of the chamber blocks.

In one embodiment, the ferrite core is installed in both the first chamber block and the third chamber block.

In one embodiment, the plasma chamber has an insulating break formed at a portion where the first chamber block, the second chamber block, and the third chamber block are joined.

According to the plasma chamber in which the installation position of the ferrite core of the present invention has been changed, the ferrite core is installed in the plasma channel provided with the gas inlet or gas outlet, thereby increasing the reaction rate between the gas supplied into the plasma chamber and the plasma to generate activated gas. This can increase the discharge rate. Additionally, the amount of gas used can be reduced by increasing the reaction rate between gas and plasma.

1 is a conceptual diagram showing a plasma chamber as a plasma source that generates activated gas.
Figure 2 is a cross-sectional view of a plasma chamber according to a first preferred embodiment of the present invention.
Figure 3 is a cross-sectional view of a plasma chamber according to a second preferred embodiment of the present invention.
Figure 4 is a cross-sectional view of a plasma chamber according to a third preferred embodiment of the present invention.
Figure 5 is a cross-sectional view of a plasma chamber according to a fourth preferred embodiment of the present invention.
Figure 6 is a cross-sectional view of a plasma chamber according to a fifth preferred embodiment of the present invention.
Figures 7 and 8 are diagrams showing various winding methods of the primary winding wound on a ferrite core.
Figure 9 is a cross-sectional view of a plasma chamber according to a sixth preferred embodiment of the present invention.
Figure 10 is a cross-sectional view of a plasma chamber according to a seventh preferred embodiment of the present invention.

In order to fully understand the present invention, preferred embodiments of the present invention will be described with reference to the accompanying drawings. Embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described in detail below. This example is provided to more completely explain the present invention to those with average knowledge in the art. Therefore, the shapes of elements in the drawings may be exaggerated to emphasize a clearer description. It should be noted that the same configuration may be indicated by the same reference numeral in each drawing. Detailed descriptions of well-known functions and configurations that are judged to unnecessarily obscure the gist of the present invention are omitted.

1 is a conceptual diagram showing a plasma chamber as a plasma source that generates activated gas.

Referring to FIG. 1, the plasma processing system consists of a process chamber 10 equipped with a substrate support 20 therein and a plasma chamber 100 for supplying activated gas to the process chamber 10 as a plasma source. . One or more sides of the plasma chamber 100 are exposed to the process chamber 10 so that charged particles generated by the plasma are in direct contact with the material to be processed (not shown). Optionally, the plasma chamber 100 is located at a distance from the process chamber 10 to allow activated gas to flow into the process chamber 10. The susceptor 20 may be located within the process chamber 10 to support a material to be processed, for example, a substrate to be processed 25 . The material to be treated may be biased relative to the potential of the plasma.

The activation gas supplied from the plasma chamber 100 may be used for cleaning the inside of the process chamber 10 or may be used for a process to process the substrate 25 mounted on the susceptor 20. . The plasma chamber 100 may use inductively coupled plasma, capacitively coupled plasma, or transformer plasma to discharge the activated gas. Among these, the plasma chamber in the present invention uses transformer plasma.

FIG. 2 is a cross-sectional view of a plasma chamber according to a first preferred embodiment of the present invention, and FIG. 3 is a cross-sectional view of a plasma chamber according to a second preferred embodiment of the present invention.

2 and 3, the plasma chamber 100 of the present invention includes a transformer that couples electromagnetic energy into a plasma formed within the plasma channel 112. The transformer includes a ferrite core 130, a primary winding 132, and a chamber block 110. The chamber block 110 allows plasma within the toroidal-shaped plasma channel 112 to form a secondary circuit of a transformer. The transformer may include additional magnetic coils and conductor coils (not shown) forming additional primary and secondary circuits. The chamber block 110 may be formed of a metallic material such as aluminum or a difficult-to-handle metal, a coated metal such as anodized aluminum, or an insulating material such as quartz. The transformer includes a power supply 102. Power supply 102 is directly connected to the primary winding 132 of the transformer.

The plasma chamber 100 may include an ignition device 120 for generating free charges that provide an initial ionization event that ignites the plasma within the toroidal-shaped plasma channel 112. The initial ionization event may be a short, high voltage pulse applied to the plasma chamber 110. Continuously high RF voltages can also be used to generate initial ionization events. Ultraviolet radiation may also be used to create free charges within the plasma channel 112, which provides an initial ionization event that ignites the plasma within the plasma channel 112. In another embodiment, ignition power is applied to the ignition electrode 122 located in the plasma chamber 100. In another embodiment, ignition power may be applied directly to primary winding 132 to provide an initial ionization event. In another embodiment, the plasma chamber 100 may be exposed to ultraviolet radiation from an ultraviolet light source (not shown) optically coupled to the chamber block 110 to trigger an initial ionization event that ignites the plasma.

Igniter 120 is installed to provide an initial ionization event into plasma channel 112. The ignition device 120 includes an insulating plate 124 installed in the open portion of the chamber block 110 and an ignition electrode 122 installed on the insulating plate 124. The ignition electrode 122 may receive power from the power supply 102 connected to the primary winding 132 to provide an initial ionization event to ignite the plasma, or may provide an initial ionization event by receiving power from a separate power source. You may. A support member 126 is provided on the top of the insulating plate 124 to support the ignition electrode 122. The ignition device 120 is equipped with an O-ring 128 for a sealed structure.

The chamber block 110 according to the present invention includes a toroidal-shaped plasma channel 112 as a discharge space for generating plasma therein. The chamber block 110 is provided with a gas inlet 114 and includes a first chamber block 110a including the upper part of the plasma channel 112, a gas outlet 116 and a lower part of the plasma channel 112. It consists of a third chamber block 110c and two second chamber blocks 110b connecting the first chamber block 110a and the third chamber block 110c. The plasma chamber 110 is divided into an upper part and a lower part based on the second chamber block 110b in which the insulating break 111 is formed. By combining the first, second, and third chamber blocks 110a, 110b, and 110c, the plasma channel 112 is formed in a toroidal shape. Here, the first chamber block 110a, the second chamber block 110b, and the third chamber block 110c may be separated into one or more parts.

The first chamber block 110a includes a plasma channel 112a that branches out to the left and right around the gas inlet 114 located in the center. The plasma channels 112a branched to the left and right are connected to the plasma channels 112 formed in the two second chamber blocks 110b. The third chamber block 110c is connected to the two second chamber blocks 110b and includes a plasma channel 112C connected to the central gas outlet 116. Therefore, the plasma channel 112 as a whole has a toroidal shape. Here, the second chamber block 110b is provided with insulating brakes 111 at both ends connected to the first chamber block 110a and the third chamber block 110c.

A ferrite core 130 may be installed in either the first chamber block 110a with the gas inlet 114 or the third chamber block 110c with the gas outlet 116, and the first chamber block The ferrite core 130 may be installed in both (110a) and the third chamber block (110c). The ferrite core 130 is installed on both sides or one side of the plasma channels 112a and 112c branched to the left and right. A primary winding 132 is wound around the ferrite core 130, and energy induced by the ferrite core 130 is provided to the plasma channels of the first chamber block 110a and the third chamber block 110c.

The gas provided through the gas inlet 114 moves along the plasma channel 112 of the second chamber block 110b. The plasma channel 112 of the second chamber block 110b is formed vertically, so the gas flows at a high speed. Go to Conventionally, since the ferrite core 130 is installed in the second chamber block 110b, the gas passing through the plasma channel 112b of the second chamber block 110b has a short reaction time with plasma. On the other hand, in the present invention, the plasma channels 112a and 112c of the first chamber block 110a and the third chamber block 110c are formed at a gentle slope, so that the gas movement path is long. Therefore, by installing the ferrite core 130 in the first and third chamber blocks 110a and 110c, the gas passing through the plasma channel 112 has a longer residence time, thereby increasing the plasma reaction time. Therefore, the activation rate of the gas discharged by reacting with the plasma within the plasma chamber 100 increases.

In addition, the length (L1) of the plasma channel 112 of the first chamber block (110a) or the third chamber block (110c) is equal to the length (L2) (length between the insulating breaks) of the two second chamber blocks (110b). Or it can be formed long. Here, L1 may refer to the horizontal length of the plasma channel 112 and may refer to the length of the plasma channel 112 provided in the first chamber block 110a or the third chamber block 110c.

The chamber block 110 includes a cooling channel (not shown) to prevent the inside of the chamber block 110 from being damaged by high-temperature plasma. A cooling channel (not shown) is located around the plasma channel 112. The cooling channel circulates coolant supplied from a coolant source (not shown) and lowers the temperature of the chamber block 110.

Figure 4 is a cross-sectional view of a plasma chamber according to a third preferred embodiment of the present invention.

Referring to FIG. 4, the plasma chamber 100a may have a plurality of ferrite cores 130 additionally installed in the second chamber 110b. Therefore, the plasma chamber 100a has a ferrite core 130 in both the first and third chamber blocks 110a and 110c and the two second chamber blocks 110b provided with the gas inlet 114 and the gas outlet 116. It is installed.

FIG. 5 is a cross-sectional view of a plasma chamber according to a fourth preferred embodiment of the present invention, and FIG. 6 is a cross-sectional view of a plasma chamber according to a fifth preferred embodiment of the present invention.

Referring to FIG. 5 , the plasma chamber 100b may be formed so that the plasma channel 112 is inclined in the chamber block 110 provided with the gas inlet 114 and the gas outlet 116. Also, referring to FIG. 6, in the plasma chamber 100c, the plasma channel 112 in the chamber block 110 may be formed in a circular shape.

Figures 7 and 8 are diagrams showing various winding methods of the primary winding wound on a ferrite core.

Referring to FIGS. 7 and 8 , the plasma chamber 100 may have a primary winding 132 wound around a plurality of ferrite cores 130 in various ways. Referring to FIG. 7, the primary winding 132 is connected to the power supply 102 and may be wound together on the first, second, third, and fourth ferrite cores (130a, 130b, 130c, and 130d). Additionally, the primary winding 132 may be connected to the power supply 102 and wound on the first and second ferrite cores 130a and 130b and then on the third and fourth ferrite cores 130c and 130d. Additionally, the primary winding 132 may be sequentially wound on each of the first, second, third, and fourth ferrite cores 130a, 130b, 130c, and 130d. Additionally, the primary winding 132 may be branched and wound on the first and second ferrite cores 130a and 130b and the third and fourth ferrite cores 130c and 130d.

Referring to FIG. 8, the primary winding 132 is connected to the power supply 102a and wound on the first and second ferrite cores 130a and 130b. Another primary winding 132 is connected to another power source 102b and wound on the third and fourth ferrite cores 130c and 130d. The two power sources 102a and 102b may supply power at the same frequency or may supply power at different frequencies.

Figure 9 is a cross-sectional view of a plasma chamber according to a sixth preferred embodiment of the present invention.

Referring to FIG. 9, the plasma chamber 200 includes an insulating break 211 formed at an oblique angle. The insulating brake 211 is provided at both ends of the second chamber block 210b connected to the first and third chamber blocks 210a and 210c. Here, since the insulating break 211 is formed at an oblique angle with respect to the plasma channel, the first and third chamber blocks 210a and 210c can each be formed as one.

The plasma chamber 200 is formed by installing a ferrite core 230 in the first and third chamber blocks 210a and 210c provided with a gas inlet 214 and a gas outlet 216. The structure and operation of installing the ferrite core 230 in the first and third chamber blocks 210a and 210c have been described in detail above and are therefore omitted. A primary winding 232 is wound around the plurality of ferrite cores 130 and connected to the power supply 202. The winding method of the primary winding 232 can be applied to the winding method in the embodiment described above.

Figure 10 is a cross-sectional view of a plasma chamber according to a seventh preferred embodiment of the present invention.

Referring to FIG. 10, the plasma chamber 300 is provided with a gas distribution unit 117 on an upper portion of a toroidal-shaped plasma channel 112. The gas distribution unit 117 is made of aluminum and is configured to uniformly distribute gas into the plasma channel 112 throughout the plasma channel 112. The gas distribution unit 117 has a gas inlet 114 at the top and a plurality of holes 118 at the bottom to communicate with the plasma channel 112. The gas supplied through the gas inlet 114 is supplied to the gas distribution unit 117 through a plurality of holes 118. Therefore, gas is uniformly supplied into the plasma channel 112, and plasma discharge occurs uniformly within the plasma channel 112. An O-ring 119 is inserted between the gas distribution unit 117 and the chamber block 110.

The embodiment of the plasma chamber in which the installation position of the ferrite core of the present invention has been changed described above is merely illustrative, and those skilled in the art will be able to make various modifications and other equivalent implementations thereof. You can see that an example is possible.

Thus, it will be understood that the present invention is not limited to the forms mentioned in the detailed description above. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims. In addition, the present invention should be understood to include all modifications, equivalents and substitutes within the spirit and scope of the present invention as defined by the appended claims.

10: Process chamber 20: Substrate support
25: susceptor 50: pump
100, 200: plasma chamber 102, 202: power source
110: Chamber block 110a: First chamber block
110b: second chamber block 110c: third chamber block
111: isolation break 112: plasma channel
114: gas inlet 116: gas outlet
120: Ignition device 122: Ignition electrode
124: insulating plate 126: support member
128: O-ring 130: Ferrite core
130a, 130b, 130c, 130d: 1st, 2, 3, 4 ferrite cores
132: Primary winding

Claims (3)

In a plasma chamber having a toroidal-shaped plasma channel,
The plasma chamber is
a first chamber block including a portion of the plasma channel and having a gas inlet for supplying gas into the plasma chamber;
a third chamber block including a portion of the plasma channel and having a gas outlet for discharging gas activated within the plasma chamber to the outside; and
A second chamber block connects the first chamber block and the third chamber block and includes a plasma channel continuous with the plasma channel,
It includes one or more ferrite cores installed in one of the first chamber block or the third chamber block to surround the plasma channel,
The ferrite core is installed in the first chamber block and disposed on both sides of the gas inlet of the first chamber block,
The ferrite core is installed in the third chamber block and disposed on both sides of the gas outlet of the third chamber block,
A plasma chamber in which the installation position of the ferrite core has been changed, wherein the length of the plasma channel of the first chamber block or the third chamber block is formed to be longer than the length of the plasma channel of the second chamber block. According to paragraph 1,
A gas distribution unit provided at an upper portion of the plasma chamber and uniformly distributing gas to the plasma channel,
The gas distribution unit,
A plasma chamber in which the installation position of the ferrite core has been changed, comprising a gas inlet formed at the top and a plurality of holes formed at the bottom of the gas inlet to communicate with the plasma channel. According to paragraph 1,
The plasma chamber is a plasma chamber in which the installation position of the ferrite core has been changed, characterized in that an insulating break is formed at a portion where the first chamber block, the second chamber block, and the third chamber block are joined.

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